import { DataSource, EntityTarget, LoggerOptions, ObjectLiteral, Repository } from 'typeorm'
import { MysqlConnectionOptions } from 'typeorm/driver/mysql/MysqlConnectionOptions'

import { TypeORMRevision } from '../Infra/TypeORM/TypeORMRevision'

import { Env } from './Env'
import { SqliteConnectionOptions } from 'typeorm/driver/sqlite/SqliteConnectionOptions'

export class AppDataSource {
  private dataSource: DataSource | undefined

  constructor(private env: Env) {}

  getRepository<Entity extends ObjectLiteral>(target: EntityTarget<Entity>): Repository<Entity> {
    if (!this.dataSource) {
      throw new Error('DataSource not initialized')
    }

    return this.dataSource.getRepository(target)
  }

  async initialize(): Promise<void> {
    this.env.load()

    const isConfiguredForMySQL = this.env.get('DB_TYPE') === 'mysql'

    const maxQueryExecutionTime = this.env.get('DB_MAX_QUERY_EXECUTION_TIME', true)
      ? +this.env.get('DB_MAX_QUERY_EXECUTION_TIME', true)
      : 45_000

    const commonDataSourceOptions = {
      maxQueryExecutionTime,
      entities: [TypeORMRevision],
      migrations: [`${__dirname}/../../migrations/${isConfiguredForMySQL ? 'mysql' : 'sqlite'}/*.js`],
      migrationsRun: true,
      logging: <LoggerOptions>this.env.get('DB_DEBUG_LEVEL', true) ?? 'info',
    }

    if (isConfiguredForMySQL) {
      const inReplicaMode = this.env.get('DB_REPLICA_HOST', true) ? true : false

      const replicationConfig = {
        master: {
          host: this.env.get('DB_HOST'),
          port: parseInt(this.env.get('DB_PORT')),
          username: this.env.get('DB_USERNAME'),
          password: this.env.get('DB_PASSWORD'),
          database: this.env.get('DB_DATABASE'),
        },
        slaves: [
          {
            host: this.env.get('DB_REPLICA_HOST', true),
            port: parseInt(this.env.get('DB_PORT')),
            username: this.env.get('DB_USERNAME'),
            password: this.env.get('DB_PASSWORD'),
            database: this.env.get('DB_DATABASE'),
          },
        ],
        removeNodeErrorCount: 10,
        restoreNodeTimeout: 5,
      }

      const mySQLDataSourceOptions: MysqlConnectionOptions = {
        ...commonDataSourceOptions,
        type: 'mysql',
        charset: 'utf8mb4',
        supportBigNumbers: true,
        bigNumberStrings: false,
        replication: inReplicaMode ? replicationConfig : undefined,
        host: inReplicaMode ? undefined : this.env.get('DB_HOST'),
        port: inReplicaMode ? undefined : parseInt(this.env.get('DB_PORT')),
        username: inReplicaMode ? undefined : this.env.get('DB_USERNAME'),
        password: inReplicaMode ? undefined : this.env.get('DB_PASSWORD'),
        database: inReplicaMode ? undefined : this.env.get('DB_DATABASE'),
      }

      this.dataSource = new DataSource(mySQLDataSourceOptions)
    } else {
      const sqliteDataSourceOptions: SqliteConnectionOptions = {
        ...commonDataSourceOptions,
        type: 'sqlite',
        database: this.env.get('DB_SQLITE_DATABASE_PATH'),
        enableWAL: true,
        busyErrorRetry: 2000,
      }

      this.dataSource = new DataSource(sqliteDataSourceOptions)
    }

    await this.dataSource.initialize()
  }
}